1059622 SzGeCERN 20240307050103.0 oai:cds.cern.ch:1059622 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN 10.1103/PhysRevC.77.064908 DOI arXiv oai:arXiv.org:0709.4507 SPIRES 7400268 Inspire 762345 arXiv arXiv:0709.4507 nucl-ex eng PACS 25.75.Gz Alt, C. Frankfurt U. Bose-Einstein correlations of $\pi^{-}\pi^{-}$ pairs in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV Bose-Einstein correlations of pion pairs in central Pb+Pb collisions at CERN SPS energies Preprint title 2008 01 Oct 2007 22 p Comments: 22 pages, 23 figures 22 pages, 23 figures arXiv Measurements of Bose--Einstein correlations of pion pairs in central Pb+Pb collisions were performed with the NA49 detector at the CERN SPS for beam energies of 20A, 30A, 40A, 80A, and 158A GeV. Correlation functions were measured in the longitudinally co-moving "out-side-long" refere nce frame as a function of rapidity and transverse momentum in the forward hemisphere of the reaction. Radius and correlation strength parameters were obtained from fits of a Gaussian parametrization. The results show a decrease of the radius parameters with increasing transverse momentum characteristic of strong radial flow in the pion source. No striking dependence on pion-pair rapidity or beam energy is observed. Static and dynamic properties of the pion source are obtained from simultaneous fits with a blast-wave model to radius parameters and midrapidity transverse momentum spectra. Predictions of hydrodynamic and microscopic models of Pb+Pb collisions are discussed. arXiv Measurements of Bose-Einstein correlations of pion pairs in central Pb+Pb collisions were performed with the NA49 detector at the CERN SPS for beam energies of 20A, 30A, 40A, 80A, and 158A GeV. Correlation functions were measured in the longitudinally co-moving ``out-side-long'' reference frame as a function of rapidity and transverse momentum in the forward hemisphere of the reaction. Radius and correlation strength parameters were obtained from fits of a Gaussian parametrization. The results show a decrease of the radius parameters with increasing transverse momentum characteristic of strong radial flow in the pion source. No striking dependence on pion-pair rapidity or beam energy is observed. Static and dynamic properties of the pion source are obtained from simultaneous fits with a blast-wave model to radius parameters and midrapidity transverse momentum spectra. Predictions of hydrodynamic and microscopic models of Pb+Pb collisions are discussed. giva LANL EDS SzGeCERN Nuclear Physics - Experiment ARTICLE CERN CERN SPS NA49 LANL EDS Nuclear Experiment nucl-ex Anticic, T. Boskovic Inst., Zagreb Baatar, B. Dubna, JINR Barna, D. Budapest, RMKI Bartke, J. Cracow, INP Betev, L. CERN Bialkowska, H. Warsaw, Inst. Nucl. Studies Blume, C. Frankfurt U. Boimska, B. Warsaw, Inst. Nucl. Studies Botje, M. NIKHEF, Amsterdam Bracinik, J. Comenius U. Bramm, R. Frankfurt U. Buncic, P. CERN Cerny, V. Comenius U. Christakoglou, P. Athens U. Chung, P. SUNY, Stony Brook, Chem. Dept. Chvala, O. Charles U. Cramer, J.G. Washington U., Seattle Csato, P. Budapest, RMKI Dinkelaker, P. Frankfurt U. Eckardt, V. Munich, Max Planck Inst. Flierl, D. Frankfurt U. Fodor, Z. Budapest, RMKI Foka, P. Darmstadt, GSI Friese, V. Darmstadt, GSI Gal, J. Budapest, RMKI Gazdzicki, M. Frankfurt U. Jan Kochanowski U. Genchev, V. Sofiya, Inst. Nucl. Res. Georgopoulos, G. Athens U. Gladysz, E. Cracow, INP Grebieszkow, K. Warsaw U. of Tech. Hegyi, S. Budapest, RMKI Hohne, C. Hoehne, C. Darmstadt, GSI Kadija, K. Boskovic Inst., Zagreb Karev, A. Munich, Max Planck Inst. Kikola, D. Warsaw U. of Tech. Kliemant, M. Frankfurt U. Kniege, S. Frankfurt U. Kolesnikov, V.I. Dubna, JINR Kornas, E. Cracow, INP Korus, R. Jan Kochanowski U. Kowalski, M. Cracow, INP Kraus, I. Darmstadt, GSI Kreps, M. Comenius U. Laszlo, A. Budapest, RMKI Lacey, R. SUNY, Stony Brook, Chem. Dept. van Leeuwen, M. NIKHEF, Amsterdam Levai, P. Budapest, RMKI Litov, L. Sofiya U. Lungwitz, B. Frankfurt U. Makariev, M. Sofiya U. Malakhov, A.I. Dubna, JINR Mateev, M. Sofiya U. Melkumov, G.L. Dubna, JINR Mischke, A. NIKHEF, Amsterdam Mitrovski, M. Frankfurt U. Molnar, J. Budapest, RMKI Mrowczynski, St. Jan Kochanowski U. Nicolic, V. Boskovic Inst., Zagreb Palla, G. Budapest, RMKI Panagiotou, A.D. Athens U. Panayotov, D. Sofiya U. Petridis, A. Athens U. Peryt, W. Warsaw U. of Tech. Pikna, M. Comenius U. Pluta, J. Warsaw U. of Tech. Prindle, D. Washington U., Seattle Puhlhofer, F. Puehlhofer, F. Philipps U. Marburg Renfordt, R. Frankfurt U. Roland, C. MIT Roland, G. MIT Rybczynski, M. Jan Kochanowski U. Rybicki, A. Cracow, INP CERN Sandoval, A. Darmstadt, GSI Schmitz, N. Munich, Max Planck Inst. Schuster, T. Frankfurt U. Seyboth, P. Munich, Max Planck Inst. Sikler, F. Budapest, RMKI Sitar, B. Comenius U. Skrzypczak, E. Warsaw U. Slodkowski, M. Warsaw U. of Tech. Stefanek, G. Jan Kochanowski U. Stock, R. Frankfurt U. Strabel, C. Frankfurt U. Strobele, H. Stroebele, H. Frankfurt U. Susa, T. Boskovic Inst., Zagreb Szentpetery, I. Budapest, RMKI Sziklai, J. Budapest, RMKI Szuba, M. Warsaw U. of Tech. Szymanski, P. CERN Warsaw, Inst. Nucl. Studies Trubnikov, V. Warsaw, Inst. Nucl. Studies Varga, D. Budapest, RMKI CERN Vassiliou, M. Athens U. Veres, G.I. Budapest, RMKI MIT Vesztergombi, G. Budapest, RMKI Vranic, D. Darmstadt, GSI Wetzler, A. Frankfurt U. Wlodarczyk, Z. Jan Kochanowski U. Wojtaszek, A. Jan Kochanowski U. Yoo, I.K. Pusan Natl. U. Zimanyi, J. Budapest, RMKI NA49 Collaboration 064908 Phys. Rev. C 77 2008 http://arxiv.org/pdf/0709.4507.pdf http://doc.cern.ch//archive/electronic/aps/PhysRevC.77.064908.pdf APS Published version, local copy http://cds.cern.ch/record/1059622/files/PhysRevC.77.064908.pdf APS Published version, local copy 491101 626608 1263691 578982 http://cds.cern.ch/record/1059622/files/arXiv:0709.4507.pdf 1263678 18366 http://cds.cern.ch/record/1059622/files/fig1_NA49_setup_pb_new.png 00000 (Color online)~The NA49 experiment: beam position detectors BPD, target foil T, time of flight detectors TOF, time projection chambers TPC, and calorimeters CAL. Details can be found in \cite{Afanasev:1999iu}. 1263679 34659 http://cds.cern.ch/record/1059622/files/fig23_FIT_PARAM_ALLEN.png 00023 (Color online)~Energy dependence of the model parameters $T$, $\rho_{0}$, $\tau_0$, $\Delta\tau$, and $R_{geo}$. Input to the fit procedure are the spectra of $\pi^{-}$ and protons, and the radii. Open symbols correspond to a fit of only the spectra, disregarding the radii. Further details and references are given in the text. 1263680 7688 http://cds.cern.ch/record/1059622/files/fig4_DCA_Det_nrows.png 00004 (Color online)~Schematic description of the anti-merging cut: two tracks have to be separated by more than $\Delta s = 2.2$ cm at more than $n_{rows} = 50$ consecutive padrows. 1263681 39959 http://cds.cern.ch/record/1059622/files/fig16_Rap_Dep_kt0.png 00016 Dependence of the fit parameters on rapidity at low $k_{t}$ at different beam energies. Filled symbols correspond to $0.0\!<\!k_{t}\!<0.1\!$~GeV/c, open symbols to ${0.1<k_{t}<0.2}$~GeV/c. 1263682 14464 http://cds.cern.ch/record/1059622/files/fig3_DCA_examles_new_rows.png 00003 (Color online)~Projections of the correlation function on the $q_{out}$ component at 158$A$~GeV beam energy at midrapidity in the transverse momentum bin $0.3<k_{t}<0.4$~GeV/c. Left hand side: requiring a distance of closest approach DCA of 1.6~cm at 10 consecutive padrows, at the right hand side: a DCA of 2.2~cm was required at 70 padrows. 1263683 23163 http://cds.cern.ch/record/1059622/files/fig20_Rapdep_at_one_kt.png 00020 (Color online)~Dependence of the BE radii on $dn/dY$ in central PbPb (AuAu) collisions. Closed symbol correspond to measurements at midrapidity, squares correspond to AGS energies, circles to SPS energies, and triangles to RHIC energies. Open symbols represent NA49 data at forward rapidity $1.0<Y_{\pi\pi}<1.5$. All radii have been interpolated to get values at $k_{t}= 0.2$~GeV/c. 1263684 32957 http://cds.cern.ch/record/1059622/files/fig9_PionsKaonsOnly.png 00009 (Color online)~Rapidity distributions of negative pions and kaons and the antiproton yield at midrapidity at SPS energies. Open symbols indicate reflected values \cite{Afanasiev:2002mx,Gazdzicki:2004ef,Alt:2006dk}. Data at 20{\it A} and 30{\it A} GeV are preliminary results. 1263685 23848 http://cds.cern.ch/record/1059622/files/fig13_DifferentCoulombs.png 00013 (Color online)~Fit parameters (158$A$ GeV, midrapidity) using various values for the mean pair separation $\langle r^{\ast} \rangle$ in the Coulomb correction procedure. Note the different scales on the the vertical axes. 1263686 10390 http://cds.cern.ch/record/1059622/files/fig10_HBT_radii_w-wo_PID.png 00010 (Color online)~$k_{t}$ dependence of fit parameters at midrapidity at 158{\it A} GeV with and without particle identification. 1263687 11625 http://cds.cern.ch/record/1059622/files/fig12_Purity_Radii_160.png 00012 (Color online)~$k_{t}$ dependence of fit parameters at midrapidity at 158{\it A} GeV assuming different values for the purity factor. 1263688 39916 http://cds.cern.ch/record/1059622/files/fig15_kt_at_SPS.png 00015 Dependence of fit parameters on $k_{t}$ at midrapidity for different beam energies. Full dots show results from this analysis, open circles indicate measurements of NA45 \cite{Adamova:2002wi}. 1263689 25601 http://cds.cern.ch/record/1059622/files/fig14_kt.png 00014 Dependence of fit parameters on $k_{t}$ at midrapidity at 158{\it A} GeV beam energy. Open symbols indicate measurements by other experiments \cite{Bearden:1998aq,Antinori:2001yi,Rosselet:2002ru,Adamova:2002wi}. 1263690 36868 http://cds.cern.ch/record/1059622/files/fig22_FIT_HBT_SPS.png 00022 (Color online)~$k_{t}$-dependence of the radius parameters in central PbPb collisions at midrapidity (data points) compared to fit results (lines). 1263692 27310 http://cds.cern.ch/record/1059622/files/fig19_EnDep_at_one_kt_back.png 00019 (Color online)~Dependence of the BE radii, the ratio $R_{out}/R_{side}$ and the volume $V_{f}$ in central PbPb (AuAu) collisions on beam energy at midrapidity. The $k_{t}$-dependence (Fig.~\ref{fig:world_data}) has been interpolated to get numerical values of the radii at $k_{t}=0.2$ GeV/c. 1263693 38274 http://cds.cern.ch/record/1059622/files/fig17_Rap_Dep_kt2.png 00017 Dependence of the fit parameters on rapidity at high $k_{t}$ at different beam energies. Filled symbols correspond to ${0.2<k_{t}<0.3}$~GeV/c, open symbols to $0.3<k_{t}<0.4$~GeV/c. 1263694 50065 http://cds.cern.ch/record/1059622/files/fig7_ExampleProjections.png 00007 (Color online)~Projections of correlations functions at midrapidity at three different beam energies at low ($0.0<k_{t}<0.1$~GeV/c) and high ($0.4<k_{t}<0.6$~GeV/c) transverse momentum. The projected components have been integrated over 50 MeV/c. The curves show the projections of the fits of Eq.~\ref{eq:finalfitting} to the data. 1263695 25671 http://cds.cern.ch/record/1059622/files/fig11_Purity_all_160GeV_KtY_Pal1.png 00011 (Color online)~The purity factor $p$ as function of $Y_{\pi\pi}$ and $k_{t}$ derived from simulations at 158{\it A} GeV beam energy. 1263696 17632 http://cds.cern.ch/record/1059622/files/fig18_worlddata.png 00018 (Color online)~Summary of the $k_{t}$ dependence of the radii at various center of mass energies at midrapidity. Data are from AGS \cite{Lisa:2000hw} (squares), this NA49 analysis (circles), PHOBOS \cite{Back:2004ug} (triangles at $\sqrt{s_{NN}}=62$~GeV), and STAR \cite{Adler:2001zd,Adams:2004yc} (triangles at $\sqrt{s_{NN}}=130,200$~GeV). 1263697 7883 http://cds.cern.ch/record/1059622/files/fig6_SplitTracks_onetrackgap.png 00006 (Color online)~Schematic description of a split track: a single track (dashed line) is reconstructed as two different tracks (solid lines). 1263698 24029 http://cds.cern.ch/record/1059622/files/fig5_RoutDCA_Pal1_rows.png 00005 (Color online)~Dependence of the parameter $R_{out}$ on the minimum separation $\Delta s$ and on the required number of rows, at midrapidity at $0.3<k_{t}<0.4$~GeV/c for the 158$A$~GeV beam energy sample. 1263699 16600 http://cds.cern.ch/record/1059622/files/fig8_HBT_radii_w-wo_MomRes.png 00008 (Color online)~Fitted radii with (triangles up) and without (triangles down) momentum semearing at midrapidity at 20{\it A} (upper) and 158{\it A} GeV (lower row) respectively. 1263700 53966 http://cds.cern.ch/record/1059622/files/fig21_FIT_SPEC_SPS.png 00021 (Color online)~Transverse mass spectra of pions, kaons, and protons in central PbPb collisions at midrapidity measured by NA49. m$_0$ is the particle rest mass. Lines indicate the fit results, numerical values of the fit parameters $T$ and $\rho_{0}$ are also shown. Further details are given in the text. 1263701 41336 http://cds.cern.ch/record/1059622/files/fig2_KTY_Draw_Paper_20_160_new.png 00001 (Color online)~Raw yields of particle pairs at 20$A$ and 158$A$ GeV beam energy as a function of ${Y_{\pi\pi}}$ and ${k_{t}}$. 2516077 9563 http://cds.cern.ch/record/1059622/files/fig00002.png 00002 noimgData sets used in this analysis. NIKHEF, Amsterdam Athens U. Comenius U. Budapest, RMKI MIT Cracow, INP Darmstadt, GSI Dubna, JINR Frankfurt U. CERN Jan Kochanowski U. Marburg U. Munich, Max Planck Inst. Charles U. Pusan Natl. U. Washington U., Seattle Sofiya U. Sofiya, Inst. Nucl. Res. SUNY, Stony Brook, Chem. Dept. Institute for Nuclear Studies, Warsaw, Poland Warsaw, Inst. Nucl. Studies Warsaw U. of Tech. Boskovic Inst., Zagreb n 200740 a2008 13 20100412 1514 CER01 20071001 PUBLIC 002716414CER ARTICLE